aboutsummaryrefslogtreecommitdiff
path: root/fs/afs/proc.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/afs/proc.c')
-rw-r--r--fs/afs/proc.c857
1 files changed, 857 insertions, 0 deletions
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
new file mode 100644
index 00000000000..9c81b8f7eef
--- /dev/null
+++ b/fs/afs/proc.c
@@ -0,0 +1,857 @@
+/* proc.c: /proc interface for AFS
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include "cell.h"
+#include "volume.h"
+#include <asm/uaccess.h>
+#include "internal.h"
+
+static struct proc_dir_entry *proc_afs;
+
+
+static int afs_proc_cells_open(struct inode *inode, struct file *file);
+static void *afs_proc_cells_start(struct seq_file *p, loff_t *pos);
+static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos);
+static void afs_proc_cells_stop(struct seq_file *p, void *v);
+static int afs_proc_cells_show(struct seq_file *m, void *v);
+static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *_pos);
+
+static struct seq_operations afs_proc_cells_ops = {
+ .start = afs_proc_cells_start,
+ .next = afs_proc_cells_next,
+ .stop = afs_proc_cells_stop,
+ .show = afs_proc_cells_show,
+};
+
+static struct file_operations afs_proc_cells_fops = {
+ .open = afs_proc_cells_open,
+ .read = seq_read,
+ .write = afs_proc_cells_write,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int afs_proc_rootcell_open(struct inode *inode, struct file *file);
+static int afs_proc_rootcell_release(struct inode *inode, struct file *file);
+static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
+ size_t size, loff_t *_pos);
+static ssize_t afs_proc_rootcell_write(struct file *file,
+ const char __user *buf,
+ size_t size, loff_t *_pos);
+
+static struct file_operations afs_proc_rootcell_fops = {
+ .open = afs_proc_rootcell_open,
+ .read = afs_proc_rootcell_read,
+ .write = afs_proc_rootcell_write,
+ .llseek = no_llseek,
+ .release = afs_proc_rootcell_release
+};
+
+static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file);
+static int afs_proc_cell_volumes_release(struct inode *inode,
+ struct file *file);
+static void *afs_proc_cell_volumes_start(struct seq_file *p, loff_t *pos);
+static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
+ loff_t *pos);
+static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v);
+static int afs_proc_cell_volumes_show(struct seq_file *m, void *v);
+
+static struct seq_operations afs_proc_cell_volumes_ops = {
+ .start = afs_proc_cell_volumes_start,
+ .next = afs_proc_cell_volumes_next,
+ .stop = afs_proc_cell_volumes_stop,
+ .show = afs_proc_cell_volumes_show,
+};
+
+static struct file_operations afs_proc_cell_volumes_fops = {
+ .open = afs_proc_cell_volumes_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = afs_proc_cell_volumes_release,
+};
+
+static int afs_proc_cell_vlservers_open(struct inode *inode,
+ struct file *file);
+static int afs_proc_cell_vlservers_release(struct inode *inode,
+ struct file *file);
+static void *afs_proc_cell_vlservers_start(struct seq_file *p, loff_t *pos);
+static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
+ loff_t *pos);
+static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v);
+static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v);
+
+static struct seq_operations afs_proc_cell_vlservers_ops = {
+ .start = afs_proc_cell_vlservers_start,
+ .next = afs_proc_cell_vlservers_next,
+ .stop = afs_proc_cell_vlservers_stop,
+ .show = afs_proc_cell_vlservers_show,
+};
+
+static struct file_operations afs_proc_cell_vlservers_fops = {
+ .open = afs_proc_cell_vlservers_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = afs_proc_cell_vlservers_release,
+};
+
+static int afs_proc_cell_servers_open(struct inode *inode, struct file *file);
+static int afs_proc_cell_servers_release(struct inode *inode,
+ struct file *file);
+static void *afs_proc_cell_servers_start(struct seq_file *p, loff_t *pos);
+static void *afs_proc_cell_servers_next(struct seq_file *p, void *v,
+ loff_t *pos);
+static void afs_proc_cell_servers_stop(struct seq_file *p, void *v);
+static int afs_proc_cell_servers_show(struct seq_file *m, void *v);
+
+static struct seq_operations afs_proc_cell_servers_ops = {
+ .start = afs_proc_cell_servers_start,
+ .next = afs_proc_cell_servers_next,
+ .stop = afs_proc_cell_servers_stop,
+ .show = afs_proc_cell_servers_show,
+};
+
+static struct file_operations afs_proc_cell_servers_fops = {
+ .open = afs_proc_cell_servers_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = afs_proc_cell_servers_release,
+};
+
+/*****************************************************************************/
+/*
+ * initialise the /proc/fs/afs/ directory
+ */
+int afs_proc_init(void)
+{
+ struct proc_dir_entry *p;
+
+ _enter("");
+
+ proc_afs = proc_mkdir("fs/afs", NULL);
+ if (!proc_afs)
+ goto error;
+ proc_afs->owner = THIS_MODULE;
+
+ p = create_proc_entry("cells", 0, proc_afs);
+ if (!p)
+ goto error_proc;
+ p->proc_fops = &afs_proc_cells_fops;
+ p->owner = THIS_MODULE;
+
+ p = create_proc_entry("rootcell", 0, proc_afs);
+ if (!p)
+ goto error_cells;
+ p->proc_fops = &afs_proc_rootcell_fops;
+ p->owner = THIS_MODULE;
+
+ _leave(" = 0");
+ return 0;
+
+ error_cells:
+ remove_proc_entry("cells", proc_afs);
+ error_proc:
+ remove_proc_entry("fs/afs", NULL);
+ error:
+ _leave(" = -ENOMEM");
+ return -ENOMEM;
+
+} /* end afs_proc_init() */
+
+/*****************************************************************************/
+/*
+ * clean up the /proc/fs/afs/ directory
+ */
+void afs_proc_cleanup(void)
+{
+ remove_proc_entry("cells", proc_afs);
+
+ remove_proc_entry("fs/afs", NULL);
+
+} /* end afs_proc_cleanup() */
+
+/*****************************************************************************/
+/*
+ * open "/proc/fs/afs/cells" which provides a summary of extant cells
+ */
+static int afs_proc_cells_open(struct inode *inode, struct file *file)
+{
+ struct seq_file *m;
+ int ret;
+
+ ret = seq_open(file, &afs_proc_cells_ops);
+ if (ret < 0)
+ return ret;
+
+ m = file->private_data;
+ m->private = PDE(inode)->data;
+
+ return 0;
+} /* end afs_proc_cells_open() */
+
+/*****************************************************************************/
+/*
+ * set up the iterator to start reading from the cells list and return the
+ * first item
+ */
+static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
+{
+ struct list_head *_p;
+ loff_t pos = *_pos;
+
+ /* lock the list against modification */
+ down_read(&afs_proc_cells_sem);
+
+ /* allow for the header line */
+ if (!pos)
+ return (void *) 1;
+ pos--;
+
+ /* find the n'th element in the list */
+ list_for_each(_p, &afs_proc_cells)
+ if (!pos--)
+ break;
+
+ return _p != &afs_proc_cells ? _p : NULL;
+} /* end afs_proc_cells_start() */
+
+/*****************************************************************************/
+/*
+ * move to next cell in cells list
+ */
+static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos)
+{
+ struct list_head *_p;
+
+ (*pos)++;
+
+ _p = v;
+ _p = v == (void *) 1 ? afs_proc_cells.next : _p->next;
+
+ return _p != &afs_proc_cells ? _p : NULL;
+} /* end afs_proc_cells_next() */
+
+/*****************************************************************************/
+/*
+ * clean up after reading from the cells list
+ */
+static void afs_proc_cells_stop(struct seq_file *p, void *v)
+{
+ up_read(&afs_proc_cells_sem);
+
+} /* end afs_proc_cells_stop() */
+
+/*****************************************************************************/
+/*
+ * display a header line followed by a load of cell lines
+ */
+static int afs_proc_cells_show(struct seq_file *m, void *v)
+{
+ struct afs_cell *cell = list_entry(v, struct afs_cell, proc_link);
+
+ /* display header on line 1 */
+ if (v == (void *) 1) {
+ seq_puts(m, "USE NAME\n");
+ return 0;
+ }
+
+ /* display one cell per line on subsequent lines */
+ seq_printf(m, "%3d %s\n", atomic_read(&cell->usage), cell->name);
+
+ return 0;
+} /* end afs_proc_cells_show() */
+
+/*****************************************************************************/
+/*
+ * handle writes to /proc/fs/afs/cells
+ * - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]"
+ */
+static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *_pos)
+{
+ char *kbuf, *name, *args;
+ int ret;
+
+ /* start by dragging the command into memory */
+ if (size <= 1 || size >= PAGE_SIZE)
+ return -EINVAL;
+
+ kbuf = kmalloc(size + 1, GFP_KERNEL);
+ if (!kbuf)
+ return -ENOMEM;
+
+ ret = -EFAULT;
+ if (copy_from_user(kbuf, buf, size) != 0)
+ goto done;
+ kbuf[size] = 0;
+
+ /* trim to first NL */
+ name = memchr(kbuf, '\n', size);
+ if (name)
+ *name = 0;
+
+ /* split into command, name and argslist */
+ name = strchr(kbuf, ' ');
+ if (!name)
+ goto inval;
+ do {
+ *name++ = 0;
+ } while(*name == ' ');
+ if (!*name)
+ goto inval;
+
+ args = strchr(name, ' ');
+ if (!args)
+ goto inval;
+ do {
+ *args++ = 0;
+ } while(*args == ' ');
+ if (!*args)
+ goto inval;
+
+ /* determine command to perform */
+ _debug("cmd=%s name=%s args=%s", kbuf, name, args);
+
+ if (strcmp(kbuf, "add") == 0) {
+ struct afs_cell *cell;
+ ret = afs_cell_create(name, args, &cell);
+ if (ret < 0)
+ goto done;
+
+ printk("kAFS: Added new cell '%s'\n", name);
+ }
+ else {
+ goto inval;
+ }
+
+ ret = size;
+
+ done:
+ kfree(kbuf);
+ _leave(" = %d", ret);
+ return ret;
+
+ inval:
+ ret = -EINVAL;
+ printk("kAFS: Invalid Command on /proc/fs/afs/cells file\n");
+ goto done;
+} /* end afs_proc_cells_write() */
+
+/*****************************************************************************/
+/*
+ * Stubs for /proc/fs/afs/rootcell
+ */
+static int afs_proc_rootcell_open(struct inode *inode, struct file *file)
+{
+ return 0;
+}
+
+static int afs_proc_rootcell_release(struct inode *inode, struct file *file)
+{
+ return 0;
+}
+
+static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
+ size_t size, loff_t *_pos)
+{
+ return 0;
+}
+
+/*****************************************************************************/
+/*
+ * handle writes to /proc/fs/afs/rootcell
+ * - to initialize rootcell: echo "cell.name:192.168.231.14"
+ */
+static ssize_t afs_proc_rootcell_write(struct file *file,
+ const char __user *buf,
+ size_t size, loff_t *_pos)
+{
+ char *kbuf, *s;
+ int ret;
+
+ /* start by dragging the command into memory */
+ if (size <= 1 || size >= PAGE_SIZE)
+ return -EINVAL;
+
+ ret = -ENOMEM;
+ kbuf = kmalloc(size + 1, GFP_KERNEL);
+ if (!kbuf)
+ goto nomem;
+
+ ret = -EFAULT;
+ if (copy_from_user(kbuf, buf, size) != 0)
+ goto infault;
+ kbuf[size] = 0;
+
+ /* trim to first NL */
+ s = memchr(kbuf, '\n', size);
+ if (s)
+ *s = 0;
+
+ /* determine command to perform */
+ _debug("rootcell=%s", kbuf);
+
+ ret = afs_cell_init(kbuf);
+ if (ret >= 0)
+ ret = size; /* consume everything, always */
+
+ infault:
+ kfree(kbuf);
+ nomem:
+ _leave(" = %d", ret);
+ return ret;
+} /* end afs_proc_rootcell_write() */
+
+/*****************************************************************************/
+/*
+ * initialise /proc/fs/afs/<cell>/
+ */
+int afs_proc_cell_setup(struct afs_cell *cell)
+{
+ struct proc_dir_entry *p;
+
+ _enter("%p{%s}", cell, cell->name);
+
+ cell->proc_dir = proc_mkdir(cell->name, proc_afs);
+ if (!cell->proc_dir)
+ return -ENOMEM;
+
+ p = create_proc_entry("servers", 0, cell->proc_dir);
+ if (!p)
+ goto error_proc;
+ p->proc_fops = &afs_proc_cell_servers_fops;
+ p->owner = THIS_MODULE;
+ p->data = cell;
+
+ p = create_proc_entry("vlservers", 0, cell->proc_dir);
+ if (!p)
+ goto error_servers;
+ p->proc_fops = &afs_proc_cell_vlservers_fops;
+ p->owner = THIS_MODULE;
+ p->data = cell;
+
+ p = create_proc_entry("volumes", 0, cell->proc_dir);
+ if (!p)
+ goto error_vlservers;
+ p->proc_fops = &afs_proc_cell_volumes_fops;
+ p->owner = THIS_MODULE;
+ p->data = cell;
+
+ _leave(" = 0");
+ return 0;
+
+ error_vlservers:
+ remove_proc_entry("vlservers", cell->proc_dir);
+ error_servers:
+ remove_proc_entry("servers", cell->proc_dir);
+ error_proc:
+ remove_proc_entry(cell->name, proc_afs);
+ _leave(" = -ENOMEM");
+ return -ENOMEM;
+} /* end afs_proc_cell_setup() */
+
+/*****************************************************************************/
+/*
+ * remove /proc/fs/afs/<cell>/
+ */
+void afs_proc_cell_remove(struct afs_cell *cell)
+{
+ _enter("");
+
+ remove_proc_entry("volumes", cell->proc_dir);
+ remove_proc_entry("vlservers", cell->proc_dir);
+ remove_proc_entry("servers", cell->proc_dir);
+ remove_proc_entry(cell->name, proc_afs);
+
+ _leave("");
+} /* end afs_proc_cell_remove() */
+
+/*****************************************************************************/
+/*
+ * open "/proc/fs/afs/<cell>/volumes" which provides a summary of extant cells
+ */
+static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file)
+{
+ struct afs_cell *cell;
+ struct seq_file *m;
+ int ret;
+
+ cell = afs_get_cell_maybe((struct afs_cell **) &PDE(inode)->data);
+ if (!cell)
+ return -ENOENT;
+
+ ret = seq_open(file, &afs_proc_cell_volumes_ops);
+ if (ret < 0)
+ return ret;
+
+ m = file->private_data;
+ m->private = cell;
+
+ return 0;
+} /* end afs_proc_cell_volumes_open() */
+
+/*****************************************************************************/
+/*
+ * close the file and release the ref to the cell
+ */
+static int afs_proc_cell_volumes_release(struct inode *inode, struct file *file)
+{
+ struct afs_cell *cell = PDE(inode)->data;
+ int ret;
+
+ ret = seq_release(inode,file);
+
+ afs_put_cell(cell);
+
+ return ret;
+} /* end afs_proc_cell_volumes_release() */
+
+/*****************************************************************************/
+/*
+ * set up the iterator to start reading from the cells list and return the
+ * first item
+ */
+static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
+{
+ struct list_head *_p;
+ struct afs_cell *cell = m->private;
+ loff_t pos = *_pos;
+
+ _enter("cell=%p pos=%Ld", cell, *_pos);
+
+ /* lock the list against modification */
+ down_read(&cell->vl_sem);
+
+ /* allow for the header line */
+ if (!pos)
+ return (void *) 1;
+ pos--;
+
+ /* find the n'th element in the list */
+ list_for_each(_p, &cell->vl_list)
+ if (!pos--)
+ break;
+
+ return _p != &cell->vl_list ? _p : NULL;
+} /* end afs_proc_cell_volumes_start() */
+
+/*****************************************************************************/
+/*
+ * move to next cell in cells list
+ */
+static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
+ loff_t *_pos)
+{
+ struct list_head *_p;
+ struct afs_cell *cell = p->private;
+
+ _enter("cell=%p pos=%Ld", cell, *_pos);
+
+ (*_pos)++;
+
+ _p = v;
+ _p = v == (void *) 1 ? cell->vl_list.next : _p->next;
+
+ return _p != &cell->vl_list ? _p : NULL;
+} /* end afs_proc_cell_volumes_next() */
+
+/*****************************************************************************/
+/*
+ * clean up after reading from the cells list
+ */
+static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
+{
+ struct afs_cell *cell = p->private;
+
+ up_read(&cell->vl_sem);
+
+} /* end afs_proc_cell_volumes_stop() */
+
+/*****************************************************************************/
+/*
+ * display a header line followed by a load of volume lines
+ */
+static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
+{
+ struct afs_vlocation *vlocation =
+ list_entry(v, struct afs_vlocation, link);
+
+ /* display header on line 1 */
+ if (v == (void *) 1) {
+ seq_puts(m, "USE VLID[0] VLID[1] VLID[2] NAME\n");
+ return 0;
+ }
+
+ /* display one cell per line on subsequent lines */
+ seq_printf(m, "%3d %08x %08x %08x %s\n",
+ atomic_read(&vlocation->usage),
+ vlocation->vldb.vid[0],
+ vlocation->vldb.vid[1],
+ vlocation->vldb.vid[2],
+ vlocation->vldb.name
+ );
+
+ return 0;
+} /* end afs_proc_cell_volumes_show() */
+
+/*****************************************************************************/
+/*
+ * open "/proc/fs/afs/<cell>/vlservers" which provides a list of volume
+ * location server
+ */
+static int afs_proc_cell_vlservers_open(struct inode *inode, struct file *file)
+{
+ struct afs_cell *cell;
+ struct seq_file *m;
+ int ret;
+
+ cell = afs_get_cell_maybe((struct afs_cell**)&PDE(inode)->data);
+ if (!cell)
+ return -ENOENT;
+
+ ret = seq_open(file,&afs_proc_cell_vlservers_ops);
+ if (ret<0)
+ return ret;
+
+ m = file->private_data;
+ m->private = cell;
+
+ return 0;
+} /* end afs_proc_cell_vlservers_open() */
+
+/*****************************************************************************/
+/*
+ * close the file and release the ref to the cell
+ */
+static int afs_proc_cell_vlservers_release(struct inode *inode,
+ struct file *file)
+{
+ struct afs_cell *cell = PDE(inode)->data;
+ int ret;
+
+ ret = seq_release(inode,file);
+
+ afs_put_cell(cell);
+
+ return ret;
+} /* end afs_proc_cell_vlservers_release() */
+
+/*****************************************************************************/
+/*
+ * set up the iterator to start reading from the cells list and return the
+ * first item
+ */
+static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
+{
+ struct afs_cell *cell = m->private;
+ loff_t pos = *_pos;
+
+ _enter("cell=%p pos=%Ld", cell, *_pos);
+
+ /* lock the list against modification */
+ down_read(&cell->vl_sem);
+
+ /* allow for the header line */
+ if (!pos)
+ return (void *) 1;
+ pos--;
+
+ if (pos >= cell->vl_naddrs)
+ return NULL;
+
+ return &cell->vl_addrs[pos];
+} /* end afs_proc_cell_vlservers_start() */
+
+/*****************************************************************************/
+/*
+ * move to next cell in cells list
+ */
+static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
+ loff_t *_pos)
+{
+ struct afs_cell *cell = p->private;
+ loff_t pos;
+
+ _enter("cell=%p{nad=%u} pos=%Ld", cell, cell->vl_naddrs, *_pos);
+
+ pos = *_pos;
+ (*_pos)++;
+ if (pos >= cell->vl_naddrs)
+ return NULL;
+
+ return &cell->vl_addrs[pos];
+} /* end afs_proc_cell_vlservers_next() */
+
+/*****************************************************************************/
+/*
+ * clean up after reading from the cells list
+ */
+static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
+{
+ struct afs_cell *cell = p->private;
+
+ up_read(&cell->vl_sem);
+
+} /* end afs_proc_cell_vlservers_stop() */
+
+/*****************************************************************************/
+/*
+ * display a header line followed by a load of volume lines
+ */
+static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
+{
+ struct in_addr *addr = v;
+
+ /* display header on line 1 */
+ if (v == (struct in_addr *) 1) {
+ seq_puts(m, "ADDRESS\n");
+ return 0;
+ }
+
+ /* display one cell per line on subsequent lines */
+ seq_printf(m, "%u.%u.%u.%u\n", NIPQUAD(addr->s_addr));
+
+ return 0;
+} /* end afs_proc_cell_vlservers_show() */
+
+/*****************************************************************************/
+/*
+ * open "/proc/fs/afs/<cell>/servers" which provides a summary of active
+ * servers
+ */
+static int afs_proc_cell_servers_open(struct inode *inode, struct file *file)
+{
+ struct afs_cell *cell;
+ struct seq_file *m;
+ int ret;
+
+ cell = afs_get_cell_maybe((struct afs_cell **) &PDE(inode)->data);
+ if (!cell)
+ return -ENOENT;
+
+ ret = seq_open(file, &afs_proc_cell_servers_ops);
+ if (ret < 0)
+ return ret;
+
+ m = file->private_data;
+ m->private = cell;
+
+ return 0;
+} /* end afs_proc_cell_servers_open() */
+
+/*****************************************************************************/
+/*
+ * close the file and release the ref to the cell
+ */
+static int afs_proc_cell_servers_release(struct inode *inode,
+ struct file *file)
+{
+ struct afs_cell *cell = PDE(inode)->data;
+ int ret;
+
+ ret = seq_release(inode, file);
+
+ afs_put_cell(cell);
+
+ return ret;
+} /* end afs_proc_cell_servers_release() */
+
+/*****************************************************************************/
+/*
+ * set up the iterator to start reading from the cells list and return the
+ * first item
+ */
+static void *afs_proc_cell_servers_start(struct seq_file *m, loff_t *_pos)
+{
+ struct list_head *_p;
+ struct afs_cell *cell = m->private;
+ loff_t pos = *_pos;
+
+ _enter("cell=%p pos=%Ld", cell, *_pos);
+
+ /* lock the list against modification */
+ read_lock(&cell->sv_lock);
+
+ /* allow for the header line */
+ if (!pos)
+ return (void *) 1;
+ pos--;
+
+ /* find the n'th element in the list */
+ list_for_each(_p, &cell->sv_list)
+ if (!pos--)
+ break;
+
+ return _p != &cell->sv_list ? _p : NULL;
+} /* end afs_proc_cell_servers_start() */
+
+/*****************************************************************************/
+/*
+ * move to next cell in cells list
+ */
+static void *afs_proc_cell_servers_next(struct seq_file *p, void *v,
+ loff_t *_pos)
+{
+ struct list_head *_p;
+ struct afs_cell *cell = p->private;
+
+ _enter("cell=%p pos=%Ld", cell, *_pos);
+
+ (*_pos)++;
+
+ _p = v;
+ _p = v == (void *) 1 ? cell->sv_list.next : _p->next;
+
+ return _p != &cell->sv_list ? _p : NULL;
+} /* end afs_proc_cell_servers_next() */
+
+/*****************************************************************************/
+/*
+ * clean up after reading from the cells list
+ */
+static void afs_proc_cell_servers_stop(struct seq_file *p, void *v)
+{
+ struct afs_cell *cell = p->private;
+
+ read_unlock(&cell->sv_lock);
+
+} /* end afs_proc_cell_servers_stop() */
+
+/*****************************************************************************/
+/*
+ * display a header line followed by a load of volume lines
+ */
+static int afs_proc_cell_servers_show(struct seq_file *m, void *v)
+{
+ struct afs_server *server = list_entry(v, struct afs_server, link);
+ char ipaddr[20];
+
+ /* display header on line 1 */
+ if (v == (void *) 1) {
+ seq_puts(m, "USE ADDR STATE\n");
+ return 0;
+ }
+
+ /* display one cell per line on subsequent lines */
+ sprintf(ipaddr, "%u.%u.%u.%u", NIPQUAD(server->addr));
+ seq_printf(m, "%3d %-15.15s %5d\n",
+ atomic_read(&server->usage),
+ ipaddr,
+ server->fs_state
+ );
+
+ return 0;
+} /* end afs_proc_cell_servers_show() */